A plug to associate an OpenAPI specification with a group of routes in a router or a controller.

It takes a :spec option with the name of a module implementing the Oaskit behaviour.

It will generally be used from a Phoenix.Router implementation:

defmodule MyAppWeb.Router do
  use Phoenix.Router

  # The provider should be called in a pipeline.
  pipeline :api do
    plug Oaskit.Plugs.SpecProvider, spec: MyAppWeb.ApiSpec
  end

  scope "/api", MyAppWeb.Api do
    # Then that pipeline can be used in one or
    # more scopes.
    pipe_through :api

    # Controllers used in such scopes can now use
    # the `Oaskit.Plugs.ValidateRequest` plug.
    get "/hello", HelloController, :hello
  end
end